A specially designed sleep questionnaire was used to assess the performance of the two hypnotic drugs. Psychiatric patients were given 5 mg nitrazepam or 10 mg temazepam in identical capsules, and were allowed more if necessary. A double-blind cross-over design was used. We found that 5-2 mg nitrazepam showed few differences from 13-2 mg temezepam. The two regimes produced fairly similar reports on patient satisfaction, quality of sleep, number of awakenings, depth of sleep and other variables. Patients on nitrazepam were a little more clear-headed in the morning, though they tended to wake later, sleep longer, and take more sleep over the 24-hour period. No toxicity was found with either drug over the 434 patient days of administration. In view of the advantages of the benzodiazepine drugs over their predecessors, we feel that it is worth exploring further the use of temazepam as a sleep inducing drug.